Showing papers on "Filter design published in 2021"

Asynchronous Fault Detection for Interval Type-2 Fuzzy Nonhomogeneous Higher-level Markov Jump Systems with Uncertain Transition Probabilities

Abstract: Based on the interval type-2 fuzzy (IT2F) approach, this paper investigates the fault detection filter design problem for a class of nonhomogeneous higher-level Markov jump systems with uncertain transition probabilities. Considering that the mode information of the system cannot be obtained synchronously by the filter, the hidden Markov model can be seen as a detector to handle this asynchronous problem, and the parameter uncertainty can be processed by the IT2F approach with the lower and upper membership functions. Then, the asynchronous IT2F filter is designed to deal with the fault detection problem. Furthermore, the Gaussian transition probability density function is introduced to describe the uncertainty transition probabilities of the system and the filter. Based on Lyapunov theory, the existence of the designed asynchronous IT2F filter and the dissipativity of the filter error system can be well ensured. The simulation study on a quarter-car suspension system verifies that the designed asynchronous IT2F filter can detect faults without error alarms.

Secure Adaptive-Event-Triggered Filter Design With Input Constraint and Hybrid Cyber Attack

Abstract: The problem of secure adaptive-event-triggered filter design with input constraint and hybrid cyber attack is investigated in this article. First, a new model of hybrid cyber attack, which considers a deception attack, a replay attack, and a denial-of-service (DoS) attack, is established for filter design. Second, an adaptive event-triggered scheme is applied to the filter design to save the limited communication resource. In addition, a novel adaptive-event-triggered filtering error model is established with the consideration of hybrid cyber attack and input constraint. Moreover, based on the Lyapunov stability theory and linear matrix inequality technique, sufficient conditions are obtained to guarantee the augmented system stability, and the parameters of the designed filter are presented with explicit forms. Finally, the proposed method is validated by simulation examples.

Finite-time asynchronous dissipative filtering of conic-type nonlinear Markov jump systems

Abstract: In the present study, the finite-time asynchronous dissipative filter design problem for the Markov jump systems with conic-type nonlinearity is studied. The hidden Markov model can describe the asynchronism embodied in the system modes and the filter modes reasonably. Moreover, a suitable Lyapunov-Krasovskii function is utilized and linear matrix inequalities are applied to obtain adequate conditions. These techniques guarantee the finite-time boundedness and strict dissipativity of the filtering error dynamic system. Furthermore, the design problems of the passive filter and the H∞ filter are studied by adjusting the three parameters $${\cal U}$$ , $${\cal G}$$ and $${\cal V}$$ . Finally, the filter gains and the optimal index α* are obtained and the correctness and feasibility of the designed approach are verified by a simulation example.

Event-based asynchronous and resilient filtering for Markov jump singularly perturbed systems against deception attacks.

Abstract: The dynamic event-based asynchronous and resilient dissipative filter design for Markov jump singularly perturbed systems (MJSPSs) against stochastic deception attacks is discussed in this paper. Firstly, a novel dynamic event-based transmission protocol is provided to further decrease the proportion of sampled data into network. The effect of deception attacks is formulated as a random variable satisfying the Bernoulli distribution. And an asynchronous filter is delicately constructed. Based on the technique of linear matrix inequality (LMI), efficient criteria of stochastically stable for the filtering error systems with a predetermined dissipative performance are obtained. An effective method of jointly design the proposed dynamic event-triggered transmission protocol and the non-synchronous filter is offered. Lastly, a numerical instance and a resistance-capacitance (RC) circuit system are provided to display the effectiveness and the benefit of the developed method.

Nonfragile Quantized $H_\infty$ Filtering for Discrete-Time Switched T–S Fuzzy Systems With Local Nonlinear Models

Abstract: This article addresses the $H_\infty$ filtering problem for a class of discrete-time nonlinear switched systems. Every subsystem of the considered nonlinear-switched systems is represented by the Takagi–Sugeno fuzzy systems with local nonlinear models. Signal quantization and filter parameter perturbation are considered simultaneously in the $H_\infty$ filter design. Both the measurement output signal and the performance output signal are quantized by two static quantizers, respectively, before they are transmitted. Based on the average dwell time approach, sufficient conditions for desired $H_\infty$ filters are established in the form of linear matrix inequalities. Under the obtained conditions, the filtering error system is exponentially stable and can achieve a weighted $H_\infty$ performance index. Finally, a numerical example and a practical example are provided to illustrate the effectiveness of the obtained results.

A Bearing Fault Diagnosis Method Based on Enhanced Singular Value Decomposition

Abstract: For the two shortcomings of singular value decomposition (SVD), the determination of the reconstruction order and the poor noise reduction ability, an enhanced SVD is introduced in this article. The core ideas include: first, an efficient method to determine the reconstructed order of SVD and the relative-change rate of the singular envelope kurtosis is presented, composed of improved SVD (ISVD). Then, the method to select the optimal node of wavelet packet transform (WPT) by the criterion of envelope kurtosis maximum is presented, composed of improved WPT (IWPT). The flexible filter design and superior noise reduction abilities of the IWPT and the passband denoise ability of the ISVD are organicly combined to form enhanced singular value decomposition (E-SVD) method. In addition, an indicator is introduced to evaluate the performance of the results. First, the reconstructed signal is obtained by performing ISVD on the original signal. Second, IWPT is executed on the reconstructed signal to achieve the optimal node. Finally, the filtered signal is combined with the envelope power spectrum to extract the bearing fault characteristic frequency. The method's validity and superiority are verified by the analysis of simulated data and actual cases of rolling bearing.

A Hierarchical Structure Approach to Finite-Time Filter Design for Fuzzy Markov Switching Systems With Deception Attacks.

Abstract: This work is concerned with the issue of finite-time filter design for a type of Takagi-Sugeno (T-S) fuzzy Markov switching system (MSSs) with deception attacks (DAs). In view of communication network security, the randomly occurring DAs are considered in the measurement output (MO), in which the malicious unknown but bounded signals are launched by the adversary. Notably, to characterize the fallibility of the communication links between the MO and the filter, the packet dropouts, DAs, and quantization effects are taken into account simultaneously, which signifies that the resulting system is much more applicable than the existing results. Meanwhile, to deal with the phenomenon of asynchronous switching, a hierarchical structure approach is adopted, which involves the existing nonsynchronous/synchronous strategy as special cases. By means of a fuzzy-basis-dependent Lyapunov strategy, sufficient criteria are formulated such that the resulting system is stochastic finite-time boundedness under randomly occurring DAs. Finally, a double-inverted pendulum model and a numerical example are provided to validate the feasibility of the attained method.

Adaptive Neural Network-Based Filter Design for Nonlinear Systems With Multiple Constraints

Abstract: Filter design for nonlinear systems, especially time delayed nonlinear systems, has always been an important and challenging problem. This brief investigates the filter design problem of nonlinear systems with multiple constraints: time delay, actuator, and sensor faults, and a new adaptive neural network-based filter design method is proposed. Comparing with the existing works where there is a shortcoming that the designed filters contain unknown time delay(s), the design method proposed in this brief overcomes the shortcoming and only the estimation of the unknown time delay exists in the filter. Furthermore, not only the system states can be estimated, but also the unknown time delay with actuator and sensor faults can be estimated in this brief. Finally, simulation results are given to show the effectiveness of the proposed new design method.

Emerging Trends in Techniques and Technology as Applied to Filter Design

Abstract: In the last decade, the filter community has innovated both design techniques and the technology used for practical implementation. In design, the philosophy has become “if you can't avoid it, use it”, a very practical engineering approach. Modes previously deemed spurious are intentionally used to create in-line networks incorporating real or imaginary transmission zeros and also reduce the number of components and thus further miniaturize; spurious responses are re-routed to increase the passband width or stopband width, frequency variation in couplings is used to create complex transfer functions, with all of these developments using what was previously avoided. Clever implementations of baluns into passive and active networks is resulting in a new generation of noise-immune filters for 5G and beyond. Finally, the use of a diakoptic approach to synthesis has appeared an evolving approach in which small blocks (“singlets”, “doublets”, etc.) are cascaded to implement larger networks, (reducing the need for very complex synthesis), with this new approach promising a large impact on the implementation of practical structures. Filter technology has migrated towards “observe it and then adapt it”, pragmatically repurposing tools not specifically originally intended for the applications. Combinations of surface wave and bulk wave resonators with L-C networks are improving the loss characteristics of filters in the region below 2 GHz. Lightweight alloys and other materials designed for spacecraft are being used in filters intended for space, to provide temperature stability without the use of heavy alloys such as Invar. Fully-enclosed waveguide is being replaced in some cases by planar and quasiplanar structures propagating quasi-waveguide modes. This is generically referred to as SIW (Substrate Integrated Waveguide). Active filters trade noise figure for insertion loss but perhaps will offer advantage in terms of size and chip-level implementation. Finally, the era of reconfiguration might be approaching, as the basic networks are evolving, perhaps lacking only the appearance of lower-loss, higher-IP solid-state tuning elements.

Fuzzy Energy-to-peak Filtering For Continuous-time Nonlinear Singular System

Abstract: This paper studies the energy-to-peak filter design problem for the continuous-time nonlinear singular systems. A Takagi-Sugeno (T-S) fuzzy model is constructed to represent the nonlinear plant. The paper focuses on the fuzzy filter design for singular systems such that the formulated filtering error system is admissible (regular, impulse-free and stable) and ensures the corresponding filtering performance in the singular systems. By introducing a novel Lyapunov function, design conditions of the fuzzy filter for the continuous-time singular systems are proposed in the light of linear matrix inequalities (LMIs) representations. Finally, a practical example and the relevant simulation results are provided to demonstrate the effectiveness and feasibility of the proposed energy-to-peak filter design approach.

Fuzzy-Affine-Model-Based Sampled-Data Filtering Design for Stochastic Nonlinear Systems

Abstract: This article addresses the sampled-data piecewise affine (PWA) filter design problem for Ito stochastic nonlinear systems represented by Takagi–Sugeno fuzzy affine models. An input delay method is used to describe the sample-and-hold behavior of the measurement output. Based on a novel piecewise quadratic Lyapunov–Krasovskii functional, some new results on the robust sampled-data PWA filtering design are proposed through a linearization procedure by using some convexification techniques. Simulation studies on a tunnel diode circuit system, and an inverted pendulum system are given to illustrate the effectiveness of the proposed method.

Design and analysis of a novel four‐channel optical filter using ring resonators and line defects in photonic crystal microstructure

Abstract: In this paper, we report a new design of an all-optical filter using photonic crystal microstructure Ring resonators, line defects, scatterer rods, microcavities, and coupling rods are used to form the filter in order to extract specific wavelengths at the output channels The well-known plane wave expansion method is used to calculate the photonic band diagram The widely used finite-difference time-domain method is also applied to study the light propagation inside the filter Our numerical results demonstrate that the proposed structure has high transmission power, high-quality factor, and low cross-talk They reveal an optical signal centered at 1522 nm exits the first output channel, which has an output-to-input ratio (OIR) of 95 % with a bandwidth (FWHM) of 04 nm, and an optical signal centered at 15208 nm exits the second output channel with an OIR of 98 % and an FWHM of 05 nm The third output channel can exit the optical signal centered at 15182 nm with an OIR of 78 % and an FWHM of 04 nm Furthermore, the fourth channel will exit the optical signal at 15193 nm with an OIR of 56 % and an FWHM of 04 nm Therefore, the quality factors of the first to fourth outputs of the filter are equal to 3805, 3041, 3795, and 3798, respectively The first to fourth outputs’ cross-talk values are also − 37 dB, − 36 dB, − 41 dB, and − 38 dB, respectively, which confirm the least interference between output channels Besides, linear dielectric rods form the filter design that leads to the filter’s appropriate performance at a low input power that is the most important benefit of this work compared to other recently published articles The maximum rise time of the proposed filter for all output ports is less than 8 ps The structure also has ​​37584 µm2, which makes the filter easy to use in photonic integrated circuits

Minimax Design of Graph Filter Using Chebyshev Polynomial Approximation

Abstract: In this brief, the minimax design problem of graph filter using Chebyshev polynomial approximation (CPA) is studied. First, conventional CPA graph filter design is investigated to show that it does not provide the minimax design, so the peak error of the spectral response of the designed filter is not minimized. Then, a spectral transformation is used to convert the minimax design problem of CPA graph filter into the one of the type-I linear-phase FIR digital filter such that the Parks-McClellan method can be employed to obtain the optimal filter coefficients of minimax design. Next, using the recurrence relation of Chebyshev polynomials, an implementation structure of CPA graph filter with low computational complexity is presented. Finally, a graph signal denoising application example is illustrated to show the usefulness of the proposed CPA graph filter.

Frequency-Reconfigurable Input-Reflectionless Bandpass Filter and Filtering Power Divider With Constant Absolute Bandwidth

Abstract: An RF input-quasi-reflectionless bandpass filter (BPF) with reconfigurable center frequency and constant absolute bandwidth (ABW) is presented. The proposed BPF is based on a tunable complementary-diplexer architecture, which is made up of a main bandpass-type channel and an auxiliary channel with nearly-complementary bandstop-type filtering response that are synchronously reconfigured in frequency. The auxiliary channel is terminated by a resistor to absorb the RF power reflected by the main channel within its out-of-band region. In this manner, input-quasi-reflectionless capability is obtained. As an original technique, the constant ABW is attained in this overall BPF across the tuning range by means of the compensation of the bandwidth variations between its two channels. Subsequently, as a further application of this filter design concept, an RF frequency-adaptive Wilkinson-type power divider (PD) with constant-ABW filtering response and input-quasi-reflectionless behavior is reported. A single resistively-terminated bandstop-type branch is connected at the input port of the filtering PD to absorb the non-transmitted RF-input-signal energy. For validation purposes, a varactor-tuned frequency-reconfigurable input-quasi-absorptive BPF and a 3-dB filtering PD with constant-ABW are built and measured.

SAR Waveform and Mismatched Filter Design for Countering Interrupted-Sampling Repeater Jamming

Abstract: The interrupted-sampling repeater jamming (ISRJ) is coherent and has the characteristic of suppression and deception to degrade the synthetic aperture radar (SAR) image quality. The anti-ISRJ methods are studied in this work in order to suppress the ISRJ based on the waveform and filter design for SAR. First, the relationship between the ISRJ and waveform is obtained by analyzing the principle of the ISRJ using the ambiguity function. The ISRJ produces multiple false targets based on the high Doppler tolerance of waveform and the characteristic of the matched filter. Next, a method is proposed to counter the ISRJ by transmitting a phase-coded (PC) waveform with low Doppler tolerance and designing the corresponding mismatched filter. The joint design method is then developed to improve the anti-ISRJ and imaging performance. In the proposed methods, the majorization minimization framework is introduced to solve the nonconvex waveform and filter design problem. Finally, several simulations are conducted to demonstrate the effectiveness of the proposed methods. Simulation results show that the joint design method shows better anti-ISRJ and imaging performance in comparison with the separate design method, but it is more sensitive to the ISRJ sampling duty ratio and period.

A Novel Filter Design Method for Grid-Tied Inverters

Abstract: Grid-tied inverters play a vital role in distribution power systems to utilize renewable energy systems. Pulsewidth modulation (PWM) techniques are used for the inverters switching, where low- and high-frequency harmonics are produced at the terminal of the inverters. Therefore, a suitable filter between the inverter and grid is needed to prevent the power quality issue in the system. LCL filters with passive damping resistor are known as well-performed solution to minimize the produced harmonics in a grid-tied topology. In this article, a unified filter design approach for a grid-tied inverter is introduced. The proposed filter design approach is based on finding the precise maximum ripple current according to the modulation method and calculating the accurate optimal passive damping resistor. Unique formulas for the calculation of active power losses are introduced, which consider all the influential designing parameters. Ultimately, a new optimization-based algorithm is presented to determine the optimal size of the inductors and capacitor considering constraints on damping losses. The experimental results prove the efficiency of the proposed optimization-based method as well as the accuracy of introduced filter parameters expressions.

Novel Concept of Solar Converter with Universal Applicability for DC and AC Microgrids

Abstract: This paper presents a novel concept of a universal solar converter suitable for application in both in the dc or single-phase ac grids using the same terminals. The idea lies in the utilization of the same semiconductors in the dc-dc and in the dc-ac configuration, resulting in minimal redundancy. Possible semiconductor stages are considered. The particular attention is focused on the output filter design along with proper protection circuit selection for dc and ac grids. The design example and comparative analysis between dc-dc, dc-ac and universal solutions are given. The experimental prototype of the universal solar converter that is rated for 3.6 kVA power in the ac mode and 5 kW in the dc mode is presented. The experimental results demonstrate the ability of operation in ac or dc grids with main correspondent modes. Possible fields of application along with main benefits are addressed in conclusions.

EMI Filter Design for a Three-Phase Buck–Boost Y-Inverter VSD With Unshielded Motor Cables Considering IEC 61800-3 Conducted and Radiated Emission Limits

Abstract: The standard converter concept employed in variable speed motor drives is the two-level three-phase Si insulated-gate bipolar transistor voltage source inverter with its switch nodes connected to the motor terminals via shielded cables to avoid excessive high-frequency noise emissions. However, high $dv/dt$ pulses of the inverter pose substantial stresses on the motor, which are further intensified by the ever-faster switching speeds of wide band-gap semiconductors, hence promoting interest in inverters with full-sinewave output filters, which potentially enable the use of inexpensive unshielded motor cables. However, the IEC 61800-3 standard dictates stringent conducted and radiated emission limits on unscreened power interfaces. In this article, a dc input and ac output filter structure allowing operation with unshielded cables is derived for a phase-modular 11-kW buck–boost Y-inverter motor drive system employing 1.2-kV SiC MOSFETs with a switching frequency of 100 kHz. First, regulations and measurement techniques for conducted and radiated emissions of motor drives are analyzed. Next, the operating principle of the Y-inverter is described and an electromagnetic interference equivalent circuit is derived, followed by a systematic filter design. Finally, measurements are conducted on an ultracompact hardware prototype of the converter system with 12 kW/dm3 (197 W/in3) power density, where the results indicate full compliance with the IEC 61800-3 conducted and radiated emission limits for operation with unshielded dc supply and motor cables in a residential area.

Dissipativity-Based Filtering for Switched Genetic Regulatory Networks with Stochastic Disturbances and Time-Varying Delays

Abstract: This paper deals with the problem of dissipativity-based filtering for switched genetic regulatory networks (GRNs) with stochastic perturbation and time-varying delays. By choosing an appropriate piecewise Lyapunov function and using the average dwell time method, we propose a new set of sufficient conditions in terms of Linear matrix inequalities (LMIs) for the existence of dissipative filter, which ensures that the resulting filtering error system is mean-square exponentially stable with dissipativity performance. The filter gains are provided by solving feasible solutions to a certain set of LMIs. A simulation example is given to demonstrate the effectiveness of the desired dissipativity-based filter design approach.

A novel approach for optimal design of digital FIR filter using grasshopper optimization algorithm

Abstract: The idea behind designing digital filters is to compute the optimal filter coefficients such that the magnitude response of the designed matches the ideal frequency response using optimization algorithms. The proposed work employed a recently proposed swarm-based optimization technique, namely, a grasshopper optimization algorithm (GOA) to design a linear phase finite impulse response (FIR) low pass, high pass, band pass , and band stop filters. This proposed algorithm models the behaviour of grasshoppers while seeking food sources to solve optimization problems. For the designing of the FIR filter, an absolute error difference fitness function is used, which is minimized using GOA to obtain optimal filter coefficients. The performance comparison of the proposed work is done with already existing algorithms such as cuckoo search, particle swarm optimization, artificial bee colony to prove its superiority and consistency. It is found that GOA based filter meets the objective efficiently with reduced ripples in pass band and higher attenuation in stop band with least execution time.

Making the PI and PID Controller Tuning Inspired by Ziegler and Nichols Precise and Reliable.

Abstract: This paper deals with the design of a DC motor speed control implemented by an embedded controller. The design is simple and brings some important changes to the traditional Ziegler–Nichols tuning. The design also includes a novel anti-windup implementation of the controller and an integrated noise-reduction filter design. The proposed tuning method considers all important aspects of the control, such as pre-processing of the measured signals and filtering (to attenuate the measurement noise), time delays of the process, modeling and identification of the process, and constraints on the control signal. Three important aspects of designing PI and PID controllers for processes with noisy output on Arduino-type embedded computers are considered. First, it deals with the integrated design of the input filter and the controller parameters, since both are interdependent. Secondly, the method of setting the controllers from step responses by Ziegler and Nichols is modified for the case of digital signal processing (without drawing the tangent), while it recommends the suitability of its modification in terms of the use of both integral and static models. Third, the most suitable anti-windup solution for the given controller structure is proposed. In summary, the paper shows that an appropriate design of the embedded controller can achieve excellent closed-loop performance even in a noisy process environment with limited control signals.

Composite Adaptive Fuzzy Finite-Time Quantized Control for Full State-Constrained Nonlinear Systems and Its Application

Abstract: This article studies the adaptive finite-time quantized tracking control problem for a class of full state-constrained nonlinear systems with unknown control directions based on a modified fractional-order dynamic surface control (FODSC) technique First, fractional calculus is introduced to filter design to avoid the issue of the ``explosion of complexity'' exposed in the traditional backstepping technique To facilitate the control design, barrier Lyapunov functions and Nussbaum gain technique are utilized to handle full state-constrained problem and the unknown control directions, respectively In addition, the fuzzy logic systems are employed to approximate the unknown nonlinearity of the system By integrating with the approximation errors and compensating signals, a composite adaptive quantized controllers is designed to guarantee all the signals of the closed-loop systems are bounded and tracking error converges to an arbitrarily small neighborhood of the zero within a finite time Finally, a mechanical horizontal platform model and a Brusselator model are carried out to verify the effectiveness of the presented control method

A Novel Ultrawideband Absorptive Common-Mode Filter Design Using a Miniaturized and Resistive Defected Ground Structure

Abstract: An ultrawideband absorptive common-mode filter (A-CMF) with a newly developed defected ground structure (DGS) is proposed in this article. The DGS miniaturized to a subwavelength size is able to totally suppress the common-mode noise while maintaining the signal integrity of the differential mode. In addition, the reflection and radiation of the common-mode noise are negligible in the stopband. For quick design, a simplified equivalent circuit model is also proposed. This model can be employed to estimate the resistances of the lumped resistors embedded in the DGS to obtain a very wide absorption band. In the demonstrated example, the fractional bandwidth determined by a 90% absorption efficiency can achieve as large as 104% around 3.55 GHz for an A-CMF realized on a simple two-layer printed circuit board. Such a widely absorptive bandwidth is never achieved before to our knowledge. The design methodology is validated by full-wave simulation. Finally, real measurement of the design is also carried out to confirm the design and analysis.

An Improved Multilevel Inverter for Single-Phase Transformerless PV System

Abstract: A single-phase Three-Level Split-Inductor Neutral Point Clamped Inverter-Improved (3L-SI-NPCI2) for transformerless photovoltaic (PV) application is proposed in this article. The proposed inverter utilizes two split inductors, which eliminate the shoot-through issue. Therefore, it is more reliable than conventional converters. Not needing dead time, achieving a high efficiency with lower current THD and low leakage current are other advantages of the proposed inverter. The operation principle, dynamic performance, output filter design and impacts of asymmetric filter inductors on leakage current are illustrated in the 3L-SI-NPCI2. The proposed topology is compared to seven existing transformerless topologies by simulation studies and results. Finally, an experimental prototype has been developed to show the benefits of the proposed inverter.

Voltage-Mode Elliptic Band-Pass Filter Based on Multiple-Input Transconductor

Abstract: This paper presents a new voltage-mode elliptic band-pass filter based on a multiple-input transconductor (MI-OTA). The MI-OTA’s structure employs the multiple-input MOS transistor technique that simply enables to increase the number of OTA’s inputs without increasing the number of current branches or the differential pairs. The MI-OTA features high linearity over a wide input range with a compact and simple CMOS structure. From the advantage of multiple inputs, it enables to construct the arbitrarily summing and subtracting under the proposed voltage-mode filter design procedure. The filter is designed and simulated in Cadence environment using $0.18~\mu \text{m}$ TSMC CMOS technology. The filter offers 72.9 dB dynamic range for 2 % total harmonic distortion (THD) for sine input signal of 0.5 Vpp @ 1kHz with voltage supply ± 0.9V. The simulation results of the filter are in agreement with the RLC prototype. The experimental results using commercially available IC are also included to confirm the proposed filter that are in good agreement with the simulation results.